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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
201

Structural, functional and energetic analysis of antibodies in complex with staphylococcal nuclease /

Perdue, Samuel Scott. January 1997 (has links)
Thesis (Ph. D.)--University of Virginia, 1997. / Spine title: Protein antigen-antibody complexes. Includes bibliographical references (198-223). Also available online through Digital Dissertations.
202

Monoclonal antibody-based sandwich ELISA for the detection of ovine muscle in cooked meat

Liu, Lihua. Hsieh, Yun-Hwa Peggy. January 2006 (has links)
Thesis (M.S.)--Florida State University, 2006. / Advisor: Yun-Hwa Peggy Hsieh, Florida State University, College of Human Sciences, Dept. of Nutrition, Food and Exercise Sciences. Title and description from dissertation home page (viewed Sept. 19, 2006). Document formatted into pages; contains viii, 75 pages. Includes bibliographical references.
203

Characterization of Caenorhabditis elegans extracellular matrix

Lee, Myeongwoo. Cheung, H. Tak. January 1997 (has links)
Thesis (Ph. D.)--Illinois State University, 1997. / Title from title page screen, viewed June 5, 2006. Dissertation Committee: H. Tak Cheung (chair), Sean Arkins, Herman E. Brockman, Paul A. Garris, Brian J. Wilkinson. Includes bibliographical references (leaves 113-121) and abstract. Also available in print.
204

Targeting CD37 and folate receptor for cancer therapy strategies based on engineered protein and liposomes /

Zhao, Xiaobin. January 2007 (has links)
Thesis (Ph. D.)--Ohio State University, 2007. / Full text release at OhioLINK's ETD Center delayed at author's request
205

Παραγωγή, απομόνωση και χαρακτηρισμός της δράσης μονοκλωνικών αντισωμάτων κατά νικοτινικών υποδοχέων της ακετυλοχολίνης

Κουτρουμπή, Σταματίνα 08 May 2012 (has links)
Οι νικοτινικοί υποδοχείς της ακετυλοχολίνης (nAChRs) είναι πενταμερή διαμεμβρανικά γλυκοπρωτεϊνικά μόρια τα οποία ανήκουν στην υπερ-οικογένεια των συνδεόμενων με προσδέτη ιοντικών καναλιών και ανάλογως με τη θέση τους στα σπονδυλωτά διακρίνονται σε νευρικού τύπου και μυϊκού τύπου. Ο μυϊκός nAChR συναντάται στη νευρομυΪκή σύναψη και έχει στοιχειομετρία (α1)2β1γδ ή (α1)2β1εδ. Στους νευρικού τύπου nAChRs, μεταξύ άλλων ανήκει και ο α4β2 υποδοχέας ο οποίος συναντάται σε υψηλά επίπεδα στον εγκέφαλο του ανθρώπου και εμφανίζεται με τη στοιχειομετρία (α4)2(β2)3 ή (α4)3(β2)2. Αποτελέσματα μελετών έχουν δείξει ότι ο υποδοχέας αυτός εμπλέκεται σε νευροεκφυλιστικές νόσους – Alzheimer, Parkinson, σχιζοφρένεια – καθώς και στον εθισμό στο κάπνισμα. Για το λόγο αυτό ο α4β2 υποδοχέας αποτελεί σημαντικό στόχο για το σχεδιασμό φαρμάκων και συνεπώς οι πληροφορίες που αφορούν τη δομή του και κυρίως το εξωκυτταρικό τμήμα του (ECD) – όπου συναντώνται οι θέσεις πρόσδεσης των προσδετών – είναι σημαντικές. Στο εργαστήριό μας έχει κατασκευαστεί και εκφράζεται στο ζυμομύκητα Pichia pastoris ένα συγκαταμερές το οποίο αποτελείται από τα ECDs των υπομονάδων β2 και α4 συνδεδεμένα σε σειρά μέσω ενός πεπτιδίου 24 αμινοξικών καταλοίπων (β2-α4). Η υψηλή υδροφιλικότητα και οι καλές ιδιότητες πρόσδεσης συνδετών αποτελούν σπουδαία πλεονεκτήματα που καθιστούν το συγκαταμερές αυτό σημαντικό μόριο για προσπάθειες κρυσταλλογραφικής ανάλυσης. Στηριζόμενοι σε αποτελέσματα μελετών που έχουν δείξει ότι μόρια που δεν κρυσταλλώνονται εύκολα μόνα τους, μπορούν να κρυσταλλωθούν ευκολότερα αν συνδεθούν με άλλα πρωτεϊνικά μόρια, έγινε η παραγωγή μονοκλωνικών αντισωμάτων (mAbs) έναντι του β2α4 ώστε τμήματα των mAbs που θα προκύψουν από πέψη αυτών με παπαΐνη (Fab τμήματα) να συγκρυσταλλωθούν μελλοντικά με το β2-α4. Στο πρώτο μέρος της εργασίας πραγματοποιήθηκε η παραγωγή mAbs έναντι του β2-α4. Για το σκοπό αυτό χρησιμοποιήθηκε η τεχνική της κυτταρικής σύντηξης μυελωματικών κυττάρων και σπληνικών κυττάρων αρουραίου ανοσοποιημένου έναντι του β2-α4. Αποτέλεσμα της μεθόδου αυτής είναι η παραγωγή υβριδωμάτων καθένα από τα οποία εκκρίνει ένα συγκεκριμένο mAb. Στη συνέχεια αυτής της διαδικασίας έγινε η επιλογή έξι υβριδώματων από τα οποία εκκρίνονταν αντίστοιχα έξι mAbs (mAbNR1-mAbNR6) με διαφορετικές ικανότητες πρόσδεσης. Πέντε από τα έξι mAbs αποδείχθηκε ότι προσδένουν είτε στη β2 είτε στην α4 υπομονάδα ενώ ένα από αυτά (mAbNR6) φαίνεται να προσδένει στη διεπιφάνεια των δύο υπομονάδων. Τα αντισώματα mAbNR2 και mAbNR3 παρουσιάζουν υψηλή ικανότητα πρόσδεσης αυστηρά για στην β2 και α4 υπομονάδα αντίστοιχα, ενώ τα υπόλοιπα αντισώματα πραγματοποιούν διασταυρούμενες αλληλεπιδράσεις και με άλλες υπομονάδες. Πειράματα με ολόκληρο τον ανθρώπινο υποδοχέα α4β2 έδειξαν ότι το mAbNR2 προσδένει και σε αυτόν, γεγονός που οδηγεί στο συμπέρασμα ότι το αντίσωμα αυτό θα μπορούσε να αποτελέσει χρήσιμο εργαλείο και για τον εντοπισμό του α4β2 υποδοχέα σε ανθρώπινο νευρικό ιστό. Στο δεύτερο μέρος της εργασίας πραγματοποιήθηκε απομόνωση και στη συνέχεια πέψη του mAbNR2 καθώς και άλλων δύο μονοκλωνικών αντισωμάτων του εργαστηρίου mAb73 (έναντι της β1 υπομονάδας του μυϊκού nAChR) και mAb198 (έναντι της α1 υπομονάδας του μυϊκού nAChR). Τα αντισώματα αυτά απομονώθηκαν από καλλιέργειες υβριδωμάτων και στη συνέχεια πραγματοποιήθηκε πέψη αυτών για τη δημιουργία Fab τμημάτων. Τα τμήματα Fab χρησιμοποιήθηκαν στη συνέχεια για τη δημιουργία συμπλόκων με τις αντίστοιχες υπομονάδες με σκοπό τη συγκρυστάλλωση. Τελικός σκοπός αυτής της διαδικασίας είναι η μελέτη της δομής των nAChRs και των υπομονάδων τους καθώς και η διευρεύνηση του τρόπου αλληλεπίδρασης αυτών με τα αντισώματα. / Nicotinic acetylcholine receptors (nAChRs) are pentameric transmembrane glycoproteins which belong to the super-family of ligand-gated ion channels. Depending on the location of the nAChRs they are categorized into two groups: muscle type and neuronal type. The muscle type nAChR is present in the neuromuscular junction with the stoichiometry (α1)2β1γδ or (α1)2β1εδ. The α4β2 receptor subtype belongs to the neuronal group, it is abundant in the human brain and its stoichiometry is (α4)2(β2)3 or (α4)3(β2)2. The α4β2 receptor is thought to be implicated in addiction to nicotine and in several neurological diseases including Alzheimer’s and Parkinson’s. For this reason this subtype is an attractive target for drug design and information concerning its extracellular domain (ECD) structure – where the ligand binding site is located – is invaluable. In our laboratory, the yeast Pichia pastoris expression system has been used for the expression of linked ECDs of α4 and β2 nAChR subunits (concatamer β2-α4). We managed to produce a hydrophilic molecule with near-native pharmacological profile for structural studies. Since several published data indicate that crystals of a molecule can be easier obtained when it is co-crystallized with an interaction partner, we produced monoclonal antibodies (mAbs) against β2-α4. Following mAb digestion with papain enzyme the produced Fab fragments will be co-crystallized with β2-α4. In the first part, mAbs against β2-α4 were produced. Rats were immunized against this molecule and their spleen cells were fused with myeloma cells. The result of this process was the production of hybridomas which secreted specific mAbs. Six hybridomas were selected for production of mAbs. These six mAbs (mAbNR1-mAbNR2) had different binding properties. Five of them (mAbNR1-mAbNR5) were anti-β2 or anti-α4 and one (mAbNR6) seemed to bind at the interface of the two subunits. mAb-NR2 and mAb-NR3 were highly specific for β2 and α4 respectively, whereas the other four mAbs exhibited some cross-reactivity with other nAChR subunits. Also, mAbNR2 could be useful for the detection of α4β2 subtype in human neuronal tissue as it shows high specificity for the human wild type α4β2 receptors. The second part of this project involved mAb purification and digestion to Fab. mAbNR2 and two other antibodies that have been previously produced in our lab (mAb73 and mAb198) were used. mAb73 binds to the β1 subunit of the muscle nAChR and mAb198 binds to α1 subunit of neuronal nAChR. These mAbs were isolated from hybridoma cultures and then digested to Fab fragments. The Fabs were then used to obtain complexes with the corresponding subunits for co-crystallization trials. The final aim of this process is to investigate the structure of nAChRs and its subunits as well as their interaction with the corresponding mAbs.
206

Obtenção de anticorpos monoclonais murinos reconhecedores de células tumorais prostáticas humanas /

Almeida, Rodrigo de, 1987- January 2017 (has links)
Orientador: Andrei Moroz / Coorientador: Ana Marisa Fusco Almeida / Banca: Elenice Deffune / Banca: Iracilda Zeppone Carlos / Resumo: O câncer de próstata (CaP) é o mais diagnosticado e a segunda causa de morte por câncer entre os homens na América e nos países da Europa Ocidental. No Brasil, o número de novos casos de CaP estimado para o ano de 2016 foi de 61.200. A forma mais letal do CaP é aquele resistente à castração, nos quais os tratamentos disponíveis conferem sobrevida média de 24 meses. Não há terapias curativas efetivas para os estágios avançados. Por essa razão, tratamentos adjuvantes associados à quimioterapia e radioterapia têm grande importância; destaque à imunoterapia passiva que utiliza anticorpos monoclonais (AcM), ferramentas que também tem relevância no diagnóstico e estadiamento da doença. Nesse sentido, esse projeto teve como objetivo principal a obtenção de um painel de AcM murinos reconhecedores de células tumorais prostáticas humanas. Para a obtenção dos AcM foi estabelecido um banco de células prostáticas e, também, de células mielomatosas murinas não secretoras de imunoglobulinas utilizadas durante todas as etapas de produção. Foram utilizados camundongos Balb/C imunizados pela técnica de imunização subtrativa com o uso da ciclofosfamida como agente tolerizador com um e dois ciclos (LNCAPS e LNCAPSS, respectivamente) e pela técnica convencional sem o uso de ciclos de tolerização (LNCAP), tendo como tolerógeno células não tumorais da linhagem RWPE-1 e como imunógeno, células tumorais da linhagem LNCaP. Após o término das imunizações, os camundongos foram sacrificados e os baços co... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Prostate cancer (PCa) is the most diagnosed and the second leading cause of cancer deaths among men in America and in Western European countries. In Brazil, the number of new cases of PCa estimated for the year 2016 was 61,200. The most lethal form of PCa is that resistant to castration, in which the available treatments confer an average survival of 24 months. However, there are no effective curative therapies for the advanced stages. For this reason, adjuvant treatments associated with chemotherapy and radiotherapy are of great importance; The use of passive immunotherapy using monoclonal antibodies (MAbs), tools that also have relevance in the diagnosis and staging of the disease. In this sense, this project had as main objective the obtaining of a panel of murine MAbs recognizing human prostatic tumor cells. In order to obtain the MAbs, a bank of prostatic cells and also nonsecretory murine myelomatosis cells used during all stages of production were established. Balb/C mice immunized by the subtractive immunization technique with the use of cyclophosphamide as a tolerant agent with one and two cycles (LNCAPS and LNCAPSS, respectively) and the conventional technique without the use of tolerance cycles (LNCAP) were used as tolerogen Non-tumor cells of the RWPE-1 lineage and as immunogen, tumor cells of the LNCaP lineage. After the immunizations were completed, the mice were sacrificed and the spleens collected to obtain lymphocytes for fusion with myelomatosis cells. A total of 12 hybridomas producing antibodies to the immunogen were obtained. The 4 best hybridomas were cloned, obtaining a total of 94 clones with positivity above 90% against the immunogen, but also 66.07% positive against the tolerogen. With the results obtained and with results obtained in related works of the group, it was concluded that the efficiency of the subtractive immunization... (Complete abstract click electronic access below) / Mestre
207

Nouveau format de banques d’anticorps recombinants humains pour un criblage fonctionnel à grande échelle / New format of human recombinant antibody libraries for functional screening at large scale

Caucheteur, Déborah 18 May 2018 (has links)
Les anticorps monoclonaux (mAb) sont depuis les années 2000 devenus des médicaments incontournables et de routine en thérapie et notamment en cancérologie. Le domaine continue à croître très rapidement et devant l’abondance des molécules disponibles, il est de plus en plus important d’apporter des molécules innovantes à haute valeur ajoutée pour la thérapie. Deux grandes approches sont utilisées pour sélectionner ces mAbs : l’hybridation lymphocytaire à partir de souris normales ou humanisées ; Les systèmes de display comme le phage-display. Les intérêts majeurs du phage display sont la rapidité de développement des mAbs, la facilité de manipulation chez E. coli, l’accès aux techniques de "protein engineering". Classiquement, les anticorps sont d’abord sélectionnés sur leur capacité de liaison à l’antigène puis ensuite testés pour leur efficacité fonctionnelle dans des modèles cellulaires. Cependant, seulement une partie de l'activité des anticorps est expliquée par leur liaison à l’antigène et l’activité thérapeutique dépend aussi fortement de leur capacité à recruter le système immunitaire (ADCC) et à activer la cascade du complément (CDC).Ce projet de thèse consiste à développer un nouveau format de banque d'anticorps recombinants combinant la puissance de la sélection par phage display à un criblage fonctionnel au format IgG entières produites en cellules eucaryotes. Ce nouveau système est basé sur des régions initiatrices hybrides contenant à la fois des promoteurs et des séquences signal procaryotes et eucaryotes permettant l’expression dans ces deux systèmes cellulaires, et des évènements de recombinaisons sites-spécifiques transférant le fragment Fab du vecteur de display vers le chromosome d’une lignée cellulaire de mammifère spécialement développée pour aboutir à la sécrétion d’un anticorps humain monoclonal par la cellule. L’approche habituelle de reclonage un par un du vecteur E. Coli au format IgG n’est plus nécessaire puisqu’il se fait directement par transfection. Ce nouveau système rend possible le couplage d’une sélection par phage display à un criblage fonctionnel direct sur une large population de clones monoclonaux humains. / Since 2000, monoclonal antibodies (mAb) have become essential and routine drugs in therapy and particularly in oncology. The field continues to grow very quickly and given the abundance of molecules available, it is increasingly important to bring innovative molecules with a high added value for therapy.Two main approaches are used to select these mAbs: hybridoma technology using normal or humanized mice; display systems such as phage-display. The major interests of phage display are the speed of mAb development, the facilities offered by E. coli and the easy access to protein engineering techniques. Typically, antibodies are first selected on their ability to bind to the antigen, and then tested for their functional efficiency in cellular models. However, only a part of the activity of antibodies is explained by their binding to the antigen, and the therapeutic activity also depends strongly on their ability to recruit the immune system (ADCC) and activate the complement cascade (CDC).This thesis project consists in the development of a new recombinant antibody library format combining the power of phage display selection with functional screening in a whole IgG format produced in eukaryotic cells. This new system is based on hybrid promoter and signal peptide regions allowing expression both in prokaryotic and eukaryotic cells, and a site-specific recombination event that exchanges the Fab between the display vector and the chromosome of an especially developed mammalian cell line resulting in the secretion of a monoclonal human antibody by the cell. The usual approach of recloning one by one from E.Coli vector to an IgG format is no more needed since it is done directly by transfection. This new system makes possible to couple selection by phage display with a direct functional screening of a large population of human monoclonal clones.
208

Análise proteômica na caracterização de anticorpos monoclonais dirigidos contra antígenos eritrocitários e leucocitários humanos

Santis, Laís Priscila de January 2018 (has links)
Orientador: Andrei Moroz / Resumo: As membranas de hemácias e leucócitos são compostas por centenas de antígenos que desempenham diversas funções relacionadas a homeostase, metabolismo celular e podem estar envolvidos em processos de rejeição de transplantes, doenças hemolíticas e reações transfusionais. Para a detecção desses antígenos são utilizados anticorpos monoclonais e a obtenção destes anticorpos envolve diversas etapas que culminam na caracterização dos produtos obtidos. Esta etapa é crítica e envolve diferentes técnicas, incluindo a Proteômica na descrição da proteína-alvo de cada anticorpo monoclonal. O objetivo deste estudo foi caracterizar anticorpos monoclonais de especificidade anti-eritrocitária e anti-leucocitária produzidos pelo Laboratório de Engenharia Celular (LEC) do Hemocentro de Botucatu. Foram selecionados um clone e um hibridoma produtores de anticorpos anti-eritrocitários, e um clone produtor de anticorpos anti-leucocitários, pertencentes ao banco de células do LEC. As células foram expandidas em cultura, foi realizado Western Blotting (WB) e cada banda proteica reconhecida pelos anticorpos (antígenos) foi analisada por Espectrometria de Massas, segundo técnicas proteômicas. Outros testes adicionais foram realizados, como técnicas imuno-hematológicas, citometria de fluxo e imuno-histoquímica. Após expansão, retestagem e verificação de reatividade contra hemácias humanas, e a seleção dos dados de outros estudos até então não explorados, na técnica de WB os anticorpos reconheceram dive... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Red blood cell and leukocyte membranes are composed of hundreds of antigens that perform various functions related to homeostasis, cell metabolism and may be involved in transplant rejection, hemolytic disease and transfusion reactions. Monoclonal antibodies are used to detect these antigens and the obtaining of these antibodies involves several steps that culminate in the characterization of the obtained products. This step is critical and involves different techniques, including Proteomics to descript the target protein of each monoclonal antibody. The aim of this study was to characterize anti-erythrocyte and anti-leukocyte monoclonal antibodies produced by the Laboratory of Cellular Engineering (LEC) of the Blood Center of Botucatu. Anti-erythrocytes clone and hybridoma antibody producers and a clone that produces anti-leukocyte antibodies, belonging to the LEC cell bank were selected. Cells were expanded in culture, it was realyzed Western Blotting (WB) technique and each protein band recognized by the antibodies (antigens) was analyzed by Mass Spectrometry according to proteomic techniques. Others tests were realized, such as immunohematology techniques, flow cytometry and immunohistochemistry. After expansion, retesting and verification of reactivity against human red blood cells, and selection of data from other studies not exploited, in the WB technique, the antibodies recognized several spots. After analysis by Mass Spectrometry, it was identified, with good reliabi... (Complete abstract click electronic access below) / Mestre
209

Produção e caracterização de anticorpos monoclonais para o vírus da dengue tipo 4

Andrade, Adriana de Souza 28 April 2015 (has links)
Submitted by Programa de Pós-graduação em Biotecnologia (mebiotec.ufba@gmail.com) on 2017-04-06T12:53:22Z No. of bitstreams: 1 Dissertação Final - Adriana Andrade.pdf: 2860120 bytes, checksum: 9c25748f97bf9e85c8b9bcc05e3f32d5 (MD5) / Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2017-06-29T14:41:03Z (GMT) No. of bitstreams: 1 Dissertação Final - Adriana Andrade.pdf: 2860120 bytes, checksum: 9c25748f97bf9e85c8b9bcc05e3f32d5 (MD5) / Made available in DSpace on 2017-06-29T14:41:03Z (GMT). No. of bitstreams: 1 Dissertação Final - Adriana Andrade.pdf: 2860120 bytes, checksum: 9c25748f97bf9e85c8b9bcc05e3f32d5 (MD5) / CAPES / O vírus da dengue (DENV) é um arbovírus pertencente à família Flaviviridae, gênero Flavivirus, apresentando quatro sorotipos denominados DENV-1, DENV-2, DENV-3 e DENV-4. No Brasil, a infecção pelo DENV-4 ressurgiu em 2010, após 31 anos, expondo a população ao alto risco de desenvolvimento da dengue grave, devido à co-circulação dos quatro sorotipos. Nesse contexto, os anticorpos monoclonais (AcM) apresentam-se como uma ferramenta importante devido à sua potencial aplicação como ferramenta biotecnológica. O objetivo deste trabalho foi a produção e caracterização de AcM contra DENV-4. A metodologia para a produção de AcM foi desenvolvida por Köhler e Milstein (1975). Resumidamente, os animais de experimentação foram hiperimunizados com antígeno viral DENV-4, obtidos a partir da multiplicação do vírus em células de cultura C6/36, e subsequente concentração e precipitação com polietilenoglicol 8000. A triagem dos sobrenadantes dos hibridomas para reatividade ao DENV-4 foi realizada pelo Ensaio Imunoenzimático (ELISA), e a caracterização dos AcM foi realizada pelas técnicas de ELISA, Dot-Blot, Imunofluorescência Indireta (IFI), Western-Blot. Um total de dez hibridomas foram obtidos e os AcM produzidos foram denominados A2, B1, B4, C11, D2, E4, F10, F12, H1, H12. Os AcM apresentaram diferentes perfis de reatividade frente aos diversos testes de detecção antigênica, demonstrando um reconhecimento direcionado principalmente para prM. Em conclusão, este estudo mostra o potencial de utilização dos AcM produzidos como insumo biotecnológico; sejam em estudos a respeito do vírus e sua patogênese, sejam em uma possível aplicação como ferramenta imunodiagnóstica. / Dengue virus (DV) is an arbovirus belonging to family Flaviviridae, genus Flavivirus, with four serotypes named DENV-1, DENV-2, DENV-3 and DENV-4. In Brazil, the infection by DENV-4 reemerged in 2010 after 31 years, exposing the population at high risk for developing severe diseases because of the co-circulation of the four serotypes. The monoclonal antibodies (AcM) are important tools due to its potential application in biotechnology. The aim of this work was to produce and to characterize of AcM against DENV-4. The methodology to produce AcM was developed by Köhler and Milstein (1975). Briefly, experimental animals were hyperimmunized with DENV-4 viral antigen obtained to virus multiplication in C6/36 culture cells and subsequent concentration and precipitation with polyethylene glycol 8000. ELISA test was performed to screen hybridoma supernatants for reactivity to DENV-4, and the characterization of AcM was performed by ELISA, Indirect Immunofluorescence (IFI), Dot-Blot and Western-Blot techniques. A total of ten hybridomas were obtained producing AcM named A2, B1, B4, C11, D2, E4, F10, F12, H1 and H12. AcM showed different reactivity profiles in the tests, showing a dominant recognition to prM. In conclusion, this study shows the potential use of AcM produced as biotechnology tool; to study the virus and its pathogenesis, or a possible application in immunodiagnostic assays.
210

Identificação, por anticorpo monoclonal, de proteína de 230 kDa relacionada com malignidade em melanoma murino / Identification of 230 kDa protein related with malignancy in murine melanoma by monoclonal antibody

Mendes, Priscila Fraga Penteado [UNIFESP] 31 December 2006 (has links) (PDF)
Made available in DSpace on 2015-07-22T20:50:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Melanomas se destacam entre os tumores sólidos por apresentar alto potencial de malignidade e incidência crescente, especialmente entre indivíduos jovens. Identificação de marcadores moleculares em melanomas é de enorme interesse para uso clínico e para estudos relacionados ao seu desenvolvimento. A linhagem de melanoma murino B16 tem sido amplamente empregada visando melhor compreensão do processo metastático. Objetivo: identificar moléculas na superfície de células B16, empregando anticorpos monoclonais, que apresentem função biológica importante para essas células, bem como investigar expressão de moléculas reconhecidas pelos mesmos mAbs em melanoma humano. Métodos: camundongos C57Bl/6 foram imunizados com células B16 irradiadas para produção de híbridos produtores de mAb. Resultados: após fusão foi obtido mAb da classe IgM, designado G12F2, que reconheceu uma única banda de aproximadamente 230 kDa em extrato total de células B16. A molécula era expressa na superfície celular e não por células não tumorigênicas, como fibroblastos ou melanócitos melan-a. Células não tumorigênicas, derivadas de melan-a, também não a expressaram ao passo que células tumorigênicas, de mesma origem, expressaram-na em grande quantidade. Variante menos metastática da linhagem B16 expressou menor quantidade desta molécula quando comparado à variante mais metastática. A neutralização da molécula de 230 kDa com mAb G12F2 inibiu proliferação, migração e invasão por células B16 in vitro. Também nestas condições, G12F2 promoveu atividade citolítica contra células B16, mediada por complemento. Por outro lado, adição in vitro de mAb G12F2 em nada alterou adesão das células B16 à fibronectina e laminina, ou adesão célula-célula. In vivo, o tratamento com mAb G12F2 inibiu crescimento do nódulo tumoral e formação de metástases pulmonares. Quando testado contra extrato de tumores de origem humana, como carcinoma e melanoma, mAb G12F2 reconheceu banda de 75 e 67 kDa, respectivamente. Por fim, foi demonstrado que mAb inibiu proliferação de células de melanoma humano in vitro. Conclusões: a molécula de 230 KDa parece ter importância durante crescimento do melanoma murino; identificação de molécula homóloga em melanoma humano fornecerá subsídios para diagnóstico e protocolos visando imunoterapia. / TEDE / BV UNIFESP: Teses e dissertações

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